The present invention relates to an apparatus for recognizing and following a target and utilizes an observation device directed toward the target which follows the target with the aid of a setting drive connected in series with a computer.
Target following systems, so-called tracking devices, are known which operate according to a contrast tracking principle. According to this principle, the scene observed by the observation device is divided into bright and dark areas, respectively, so that, for example, all bright areas are considered the target, all dark areas are considered as background (or vice versa) and the center of gravity of an area which has been recognized as the target is computed. Alternatively, the position of a bright/dark edge can be determined. When the target moves, a deviation signal is transmitted to a servo system which effects adjustment of the observation system or device to correspond to the deviation signal. Known embodiments of such target tracking systems are search heads with guadrant detectors or certain television tracking devices. All these devices have in common the utilization of the information "by contrasting the target against the background". This has the result, for example, that in this manner it is easy to follow a flying object since it generally appears dark with high contrast before a bright background. However, such a device fails if a target having average gray values is to be followed before a background with portions of different nature.
Target tracking devices are also known which evaluate the structure of the tracked target. A known device operates according to an optical process in which a space Fourier component of a target is examined as to its phase with respect to the shifted target position at a later time. The servo system regulates the observation device to a phase position which is constant in time. Since, however, the entire target structure cannot be stored, it is impossible, for example, to relocate a target once it has been lost.